The present invention relates generally to additive manufacturing and, more particularly, to additive manufacturing using powder bed fusion.
Additive manufacturing technology can be used for building component designs that were not previously possible using conventional machining methods, such as complex fuel passages and heat shields. In addition to the ability to build components having complex geometry, additive manufacturing can also eliminate weak junctures, such as seams and braze or weld joints. Typical additive manufacturing methods, such as powder bed fusion, produce completed parts with extremely rough surface finishes. A rough surface finish can be detrimental to the function of some components, such as atomizer fuel circuit exit passages, which require very smooth surfaces to control flow number and atomizer spray uniformity.
Current methods of resolving surface finish issues include machining accessible additively manufactured passages to control surface finish, which is very time consuming and limited by the small portion of the fuel passage which is externally accessible. Another method of resolving surface finish is to braze or weld machined parts, which is costly and difficult to execute due to space requirements of some components, such as atomizer tips. Other methods that improve the surface finish of internal passages are problematic because it is difficult to control which areas are smoothed and which are not.